Modular medical injection system

ABSTRACT

A medical injection system includes an elongate injection apparatus and an actuator apparatus. The actuator apparatus includes a fitting for coupling the actuator apparatus to a delivery catheter and a reversible gripping means to grip the injection apparatus; the gripping means is included in a plunger that is slideably engaged with the fitting and directs the injection apparatus through a fitting lumen and through a catheter lumen, when the fitting is coupled to the catheter.

RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.10/867,059, filed Jun. 14, 2004 entitled “MODULAR MEDICAL INJECTIONSYSTEM”, herein incorporated by reference in its entirety.

TECHNICAL FIELD

The present invention relates generally to medical systems fordelivering therapeutic agents and more particularly to elements of amodular injection system.

BACKGROUND

Because a therapeutic agent, for example pharmacological, genetic, orbiological, may be ineffective or even toxic when deliveredsystemically, tools and methods for delivering therapeutic agentslocally, that is, to a targeted tissue site, have been developed.

Many state-of-the art steerable catheters have lumens through whichagents may be delivered. Rather than modifying state-of-the-artsteerable catheter designs to integrally incorporate specific deliverymechanisms, such as means to inject agents into a tissue site, it isdesirable to provide modular apparatuses, which can be coupled to any ofsuch state-of-the-art steerable catheters and which include desiredspecific delivery mechanisms.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings are illustrative of particular embodiments of theinvention and therefore do not limit its scope, but are presented toassist in providing a proper understanding of the invention. Thedrawings are not to scale (unless so stated) and are intended for use inconjunction with the explanations in the following detailed description.The present invention will hereinafter be described in conjunction withthe appended drawings, wherein like numerals denote like elements, and:

FIG. 1 is a plan view of a modular medical injection system according toone embodiment of the present invention;

FIG. 2 is a perspective sectional view of an actuator apparatus andinjection apparatus of the system shown in FIG. 1;

FIG. 3 is a section view of another member of a modular injection systemaccording to one embodiment of the present invention;

FIG. 4 is a plan view of the injection apparatus shown in FIG. 1according to one embodiment of the present invention;

FIG. 5 is an enlarged detailed view of a portion of the injectionapparatus shown in FIG. 4 according to some embodiments of the presentinvention; and

FIGS. 6A-D are partial section views of distal portions of injectionapparatuses according to alternate embodiments of the present invention.

DETAILED DESCRIPTION

The following detailed description is exemplary in nature and is notintended to limit the scope, applicability, or configuration of theinvention in any way. Rather, the following description provides apractical illustration for implementing exemplary embodiments of theinvention.

FIG. 1 is a plan view of a modular medical injection system according toone embodiment of the present invention. FIG. 1 illustrates the systemincluding a delivery catheter 120 to which an actuator 100 is joined bymeans of a coupling or connector 12 terminating a distal end of anactuator fitting 104; a lumen (not shown), which extends through a shaft123 and a handle 122 of catheter 120 and through actuator 100, slideablyengages an injection apparatus 110 whose needle tip 114 is shownextending out from a catheter distal end 125. FIG. 1 further illustratesinjection apparatus 110 including an elongate shaft 112 and a fitting 3terminating a proximal end of shaft 112, fitting 3 being adapted tocouple injection apparatus 110 to a source, for example a syringe, forinjection of therapeutic agents from the source through a lumen 113(FIG. 4) of injection apparatus 110. According to the illustratedembodiment, actuator 100 further includes a plunger 105 slideablyengaged with fitting 104; plunger 105 includes a valve 11, forreversibly gripping shaft 112 of injection apparatus 110 so that when anoperator forces plunger 105 toward fitting 104 per arrow A, shaft 112,being gripped by valve 11, is forced distally through catheter 120 sothat needle tip 114 moves out from catheter distal end 125 to pierce atarget tissue site in proximity to distal end 125. FIG. 1 furtherillustrates plunger 105 and fitting 104 each including radiallyextending surfaces 5 and 4, respectively, to facilitate operatorhandling to perform this operation.

According to embodiments of the present invention, catheter 120 may beany delivery catheter, known to those skilled in the art, that includesa compatible coupling for connector 12, for example a luer coupling; butcatheter 120 is preferably selected from a group of steerable cathetersknown to those skilled in the art, for example those that would includemanipulator means incorporated into a handle, i.e. handle 122illustrated in FIG. 1, the manipulator means causing deflection ofcatheter shaft 123 to facilitate positioning of catheter distal end 125at the target tissue site.

FIG. 2 is a perspective sectional view of one embodiment of actuatorapparatus 100 and injection apparatus 110 of the system shown in FIG. 1.FIG. 2 illustrates injection apparatus 110 having been positioned withinactuator apparatus 100 by passing needle tip 114 (FIG. 1) into openedvalve 11, through lumens of plunger 105 and fitting 104, and then outthrough connector 12. According to an exemplary embodiment, molded rigidplastics, examples of which include polycarbonate, polyethylene andpolypropylene, form plunger 105 and fitting 104.

FIG. 2 further illustrates fitting 104 including a spring member 10,which is mounted at an interface between plunger 105 and fitting 104, aside port 14, which is terminated by a stop cock 13 and in fluidcommunication with the lumen of fitting 104, for flushing a lumen of acatheter to which fitting will be coupled, and a septum 7, which is heldin place by a septum cap 6, for sealing plunger 105 from the catheterlumen, while allowing passage of injection apparatus 110 therethrough.According to the illustrated embodiment, spring member 10 holds plunger9 in a retracted position until a force is applied to slide plunger 105distally with respect to fitting 104. When this force is applied, valve11, which is illustrated here as a Touhy-Borst type, will have beentightened, according to means known to those skilled in the art, suchthat internal walls of a compressible member 1 protrude into the lumenof plunger 105 to grip injection apparatus 110 so that injectionapparatus 110 is advanced distally along with plunger 105. It should benoted that the scope of the present invention covers other means forreversibly gripping injection apparatus 110 known to those skilled inthe art, examples of which include, but are not limited to, 3-jaw chucksand set screws. FIG. 2 further illustrates injection apparatus 110including a grip tube 9 positioned around shaft 112 (further illustratedin FIG. 4), which enlarges an outer diameter of shaft 112 to facilitategripping of injection apparatus 110 by valve 11; grip tube 9 may furtherenhance gripping by means of a corrugated or soft and/or tacky outersurface.

According to one embodiment of the present invention, an introducer 30as illustrated in section view in FIG. 3 is used to facilitate insertionof injection apparatus 110 through actuator apparatus 100. FIG. 3illustrates introducer 30 including an introducer shaft 34 coupled to anintroducer handle 32 and a lumen 36 extending through an entire lengthof introducer 30; according to one embodiment, a length of shaft 34 issufficient to extend within actuator apparatus 100 from connector 12through valve 11 (FIG. 2) so that lumen 36 may provide a smooth passagefor injection apparatus 110 through an entire length of actuator 100.According to one method, a first end 366 of introducer 30 would beinserted into actuator 100 at connector 12 and passed through actuator100 until first end 366 extends out from valve 11; then needle tip 114(FIG. 1) would be inserted into lumen 36 at first end 366 and passedthrough until tip 114 protrudes from a second end 362 of introducer 30;finally introducer 30 would be removed from actuator 100 and fitting 104may then be coupled to a catheter.

Returning now to FIG. 1, a method for advancing injection apparatus 110through catheter 123, according to one embodiment of the presentinvention, will be described. Upon coupling actuator 100 to catheter120, an operator may advance injection apparatus 110 through catheteruntil needle tip 114 is approximately flush with catheter distal end125, at which time valve 11 is closed to grip injection apparatus 110;thus, injection apparatus 110 is held in place within catheter 120 whilethe operator advances catheter 120 to a target tissue site. Once theoperator has positioned catheter distal tip 125 in close proximity tothe target site, the operator causes plunger 105 to advance distally,thereby pushing needle tip 114 of injection apparatus 110 into the site;either in conjunction with or following plunger action, a therapeuticagent is injected through injection apparatus 110 from a source oftherapeutic agent which is coupled to injection apparatus 110, viafitting 3. According to the embodiment illustrated in FIG. 2, actuatorapparatus 100 includes a stop in the form of a pin 8 extending intofitting 104 and interfacing with a depression 18 formed on plunger 105;the stop is designed to limit the plunger travel according to aprescribed injection depth. Finally, after injection of the therapeuticagent is completed, the operator allows plunger 105 to retract by meansof the spring force previously described.

FIG. 4 is a plan view of injection apparatus 110 according to oneembodiment of the present invention. FIG. 4 illustrates injectionapparatus 110 including a modified distal portion 40 of shaft 112;distal portion 40 extends from an end 44 of a proximal portion of shaft112 to a distal end 42 of shaft 112 and is modified for increasedflexibility relative to the proximal portion of shaft 112. FIG. 4further illustrates needle tip 114 extending from shaft distal end 42;according to some embodiments needle tip 114 is an independent member,which has been fixedly coupled to shaft 112 in proximity to distal end42. Examples of appropriate needle tips include, but are not limited to,20-25 gauge stainless steel tips.

Dashed lines in FIG. 4 indicate lumen 113 of shaft 112 extending frominjection apparatus fitting 3 to needle tip 114 and approximatelyaligned with a lumen 115 of needle tip; lumens 113, 115 are adapted todeliver therapeutic agents out through needle tip 114 when tip 114 hasbeen inserted into a target tissue site. Shaft may be formed from anyappropriate biocompatible material known to those skilled in the art,which has sufficient strength and rigidity to accommodate lumen 113 andto push needle tip 114 into a target tissue site; one such material isstainless steel, for example 304 or 316L stainless steel. Because apathway to a target tissue site may include a number of bends, which canbe more acute closer to the target site, modified distal portion 40decreases the inherent rigidity of shaft 112 over the length of distalportion 40 to improve tracking of injection apparatus 110 throughcatheter 120 to the target site.

FIG. 5 is an enlarged detailed view of distal portion 40 of injectionapparatus 110 according to some embodiments of the present invention.FIG. 5 illustrates distal portion 40 including a spiral cut extendingalong segments A, B and C; according to the illustrated embodiment apitch of spiral cut varies along portion 40 from a maximum or mostproximal pitch PP to a minimum pitch P1. FIG. 5 further illustratessegment C having an exponentially decreasing pitch from end 44 distally,segment B having a constant pitch, segment A having a linearlydecreasing pitch from P2 to P1, and a non-cut segment D terminatingsegment A. According to embodiments of the present invention, the spiralcut is formed through an entire wall thickness of shaft distal portion40. Appropriate methods for making the spiral cut are known to thoseskilled in the art, one example of which is laser cutting, and,according to preferred embodiments, a kerf width is betweenapproximately 0.015 mm and approximately 0.035 mm.

Examples of modified distal portion 40, included among embodiments ofthe present invention, are described in the following table:

Segment C Wherein pitch is Segment A blended exponen- Segment B Whereinpitch tially decreasing Wherein pitch decreases linearly from ~4.9 mm is~ from ~0.75 mm to ~0.8 mm. constant. to ~0.5 mm Example 1 Length ≅ 75mm Length ≅ 40 mm Length ≅ 3.75 mm Example 2 Length ≅ 100 mm Length ≅100 mm Length ≅ 3.75 mm Example 3 Length ≅ 200 mm Length ≅ 100 mm Length≅ 3.75 mm Example 4 Length ≅ 300 mm Length ≅ 100 mm Length ≅ 3.75 mm

According to the exemplary embodiments, an overall length of injectionapparatus 110 is approximately 150 cm and an outer diameter is betweenapproximately 0.6 mm and approximately 0.7 mm.

FIGS. 6A-D are partial section views of distal portions of injectionapparatuses according to alternate embodiments of the present invention.FIG. 6A illustrates a needle tip 64 inserted into distal end 42 of shaft112 such that a proximal end 641 is in proximity to distal end 42, whileFIGS. 6B-C illustrate needle tips 640 and 604 that extend into shaft 112beneath an entire length of distal portion 40 such that tip proximalends 642 and 602, respectively, are positioned proximal to end 44.Needle tips 64, 640 and 604 may be formed of stainless steel, Nitinol,or any other appropriate needle material known to those skilled in theart.

According to the embodiment illustrated in FIG. 6A, needle tip 64 isfixedly coupled to shaft 112 by means of a joint 61, which may be formedby adhesive bonding, laser welding, mechanical crimping or any othersuitable means known to those skilled in the art. FIG. 6A furtherillustrates an outer layer 60 formed about distal portion 40; accordingto the spiral cut embodiments, layer 60 prevents leakage of therapeuticagents out through the cuts. Outer layer 60 may be extruded over distalportion 40 or, in the form of a previously extruded tube, fitted overportion 40 and bonded in place, for example with an adhesive or by laserenergy; examples of suitable materials for such outer layers include butare not limited to polyether block amides (PEBAX), polyurethanes,polyethylenes and silicones. According to alternate embodiments, outerlayer 60 is a tube, which has been fitted over distal portion 40 andheat shrunk into relatively tight conformance with an outer surface ofportion 40; examples of suitable materials for a shrink-fit outer layerinclude, but are not limited to, polyesters and fluoropolymers. One suchexemplary embodiment incorporates a polyester shrink tube, availablefrom Advanced Polymers of New Hampshire, having an inner diameter ofapproximately 0.029 inch and a wall thickness of approximately 0.00025inch. FIG. 6B illustrates an alternate embodiment in which outer layer60 is not included; rather a seal 65, for example made from siliconerubber, is positioned about an outer surface of needle tip 640, proximalto end 44, and engages an inner surface of shaft 112 to prevent passageof agents out through the spiral cuts of portion 40. FIG. 6B furtherillustrates needle tip 640 fixedly coupled to shaft by both joint 61 anda second joint 62.

FIG. 6C illustrates needle tip 604 tapering from proximal end 602 todistal end 601 wherein proximal end 602 is wedged within shaft 112. FIG.6C further illustrates outer layer 60 formed about portion 40 and ajoint 67 formed between needle tip 604 and shaft distal end 42.According to one embodiment, joint 67 solely fixedly couples tip 604 toshaft 112 and, according to another embodiment, joint 67 not onlycouples but further provides sealing between tip 604 and shaft distalend 42 (as illustrated by dashed lines), if proximal end 602 is notsealed within shaft. An adhesive backfill, a laser weld, or a mechanicalcrimp may form joint 67.

FIG. 6D illustrates an outer layer 605 extending over distal portion 40and over a portion of needle tip 640 just distal to shaft distal end 42;layer 605 may be formed in any manner similar to those described forlayer 60 and may be selected from the same group of materials. FIG. 6Dfurther illustrates a seal 650 positioned between needle tip 640 andouter layer 605. It should be noted that shorter needle tip 64,illustrated in FIG. 6A could be incorporated into this embodiment aswell.

In the foregoing detailed description the invention has been describedwith reference to specific embodiments. However, it may be appreciatedthat various modifications and changes can be made without departingfrom the scope of the invention as set forth in the appended claims.

1-76. (canceled)
 77. A medical delivery system, comprising: an elongatedelivery apparatus comprising: an elongate shaft including a shaft lumenextending from a proximal end of the shaft to a distal end of the shaft,a proximal portion extending distally from the proximal end, and adistal spiral cut portion extending distally from the proximal portionto the distal end of the shaft, the distal spiral cut portion comprisinga first segment extending distally from the proximal portion, a secondsegment extending distally from the first segment, and a spiral cutextending along the first segment and second segment, the spiral cuthaving a pitch that decreases at a first rate within the first segmentand a pitch that decreases at a second rate within the second segment,wherein the first and second rates are different; and a needle tipcoupled to the shaft and extending distal to the distal end of theshaft, the needle tip including a needle lumen extending therethroughand approximately aligned with the shaft lumen; and an actuatorapparatus comprising: a fitting for coupling the actuator apparatus to aproximal portion of a catheter, the fitting including a fitting lumenconfigured to receive the needle tip and the elongate shaft of thedelivery apparatus and to direct the needle tip and the elongate shaftof the delivery apparatus through a catheter lumen of the catheter; anda plunger slidably engaged with the fitting, the plunger including aplunger lumen configured to slidably receive the needle tip and theelongate shaft of the delivery apparatus and to direct the needle tipand elongate shaft through the fitting lumen; wherein the plunger isconfigured to reversibly grip the elongate shaft of the deliveryapparatus such that moving the plunger distally and proximally moves theneedle tip and elongate shaft of the delivery apparatus distally andproximally relative to the catheter lumen when the actuator apparatus iscoupled to the catheter and the elongate shaft is gripped by theplunger.
 78. The system of claim 77, wherein the first rate at which thepitch decreases within the first segment is a generally exponentiallydecreasing rate.
 79. The system of claim 77, wherein the second rate atwhich the pitch decreases within the second segment is a generallylinearly decreasing rate.
 80. The system of claim 77, wherein the firstrate at which the pitch decreases within the first segment is agenerally exponentially decreasing rate, and wherein the second rate atwhich the pitch decreases within the second segment is a generallylinearly decreasing rate.
 81. The system of claim 77, wherein theplunger comprises a valve configured to reversibly grip the elongateshaft of the delivery apparatus.
 82. The system of claim 77, wherein theactuator apparatus further comprises an elastomeric plug positionedbetween the plunger and the catheter lumen, wherein the elastomeric plugseals the plunger from the catheter lumen while allowing passage of theelongate shaft of the delivery apparatus.
 83. The system of claim 77,wherein the actuator apparatus fitting further includes a Luer threadconfigured to couple with the catheter.
 84. The system of claim 77,wherein the actuator apparatus further comprises a spring member mountedbetween the plunger and the fitting to hold the plunger in a retractedposition until a force is applied to slide the plunger distally withrespect to the fitting.
 85. The system of claim 77, further comprisingan introducer configured to pass through the fitting lumen and theplunger lumen of the actuator apparatus, the introducer including anintroducer lumen extending therethrough that is configured to receivethe needle tip and the elongate shaft of the delivery apparatus.
 86. Thesystem of claim 77, wherein the distal spiral cut portion of theelongate shaft further includes at third segment extending distallybetween the first segment and the second segment, the spiral cut havinga generally constant pitch along the third segment.
 87. The system ofclaim 77, wherein the elongate shaft further comprises an outer layerextending over the distal spiral cut portion.
 88. The system of claim87, wherein the outer layer has a wall thickness less than or equal toapproximately 0.05 mm.
 89. The system of claim 87, wherein the outerlayer comprises a polymer.
 90. The system of claim 86, wherein thedistal spiral cut portion of the elongate shaft has a length betweenapproximately 50 mm and 500 mm.
 91. The system of claim 77, wherein thedelivery apparatus further comprises a grip tube positioned about theelongate shaft, wherein the grip tube is closer to the proximal end thanthe distal end of the elongate shaft.
 92. A medical delivery systemcomprising: an elongate delivery apparatus comprising: an elongate shaftincluding a shaft lumen extending distally from a proximal end of theshaft to a distal end of the shall, a proximal portion extending fromthe proximal end, and a distal spiral cut portion extending distallyfrom the proximal portion to the distal end of the shaft, the distalspiral cut portion comprising a first segment extending distally fromthe proximal portion, a second segment extending distally from the firstsegment, and a spiral cut extending along the first segment and secondsegment, the spiral cut having a first pitch within the first segmentand a second pitch within the second segment, wherein the first pitch isdifferent than the second pitch; and a needle tip coupled to the shaftand extending distal to the distal end of the shaft, the needle tipincluding a needle lumen extending therethrough and approximatelyaligned with the shaft lumen; and an actuator apparatus comprising: afitting for coupling the actuator apparatus to a proximal portion of acatheter, the fitting including a fitting lumen configured to receivethe needle tip and the elongate shaft of the delivery apparatus and todirect the needle tip and the elongate shaft of the delivery apparatusthrough a catheter lumen of the catheter; and a plunger slidably engagedwith the fitting, the plunger including a plunger lumen configured toslidably receive the needle tip and the elongate shaft of the deliveryapparatus and to direct the needle tip and elongate shaft through thefitting lumen; wherein the plunger is configured to reversibly grip theelongate shaft of the delivery apparatus such that moving the plungerdistally and proximally moves the needle tip and elongate shaft of thedelivery apparatus distally and proximally relative to the catheterlumen when the actuator apparatus is coupled to the catheter and theelongate shaft is gripped by the plunger.
 93. The system of claim 92,wherein the first pitch within the first segment is a generally constantpitch.
 94. The system of claim 92, wherein the second pitch within thesecond segment is a generally linearly decreasing pitch.
 95. The systemof claim 92, wherein the first pitch within the first segment is agenerally constant pitch, and wherein the second pitch within the secondsegment is a generally linearly decreasing pitch.
 96. The system ofclaim 92, wherein the plunger comprises a valve configured to reversiblygrip the elongate shaft of the delivery apparatus.
 97. The system ofclaim 92, wherein the actuator apparatus further comprises anelastomeric plug positioned between the plunger and the catheter lumen,wherein the elastomeric plug seals the plunger from the catheter lumenwhile allowing passage of the delivery apparatus.
 98. The system ofclaim 92, wherein the actuator apparatus further comprises a springmember mounted between the plunger and the fitting to hold the plungerin a retracted position until a force is applied to slide the plungerdistally with respect to the fitting.
 99. The system of claim 92,further comprising an introducer configured to pass through the fittinglumen and the plunger lumen, the introducer including an introducerlumen extending therethrough that is configured to slidably receive theneedle tip and the elongate shaft of the delivery apparatus.
 100. Thesystem of claim 92, wherein the distal spiral cut portion of theelongate shaft of the delivery apparatus further includes a thirdsegment extending distally between the proximal portion and the firstsegment, the spiral cut having a generally exponentially decreasingpitch along the third segment.
 101. The system of claim 92, wherein thedelivery apparatus further comprises an outer layer extending over thedistal spiral cut portion.
 102. The system of claim 101, wherein theouter layer comprises a polymer.
 103. The system of claim 92, whereinthe length of the distal spiral cut portion is between approximately 50mm and approximately 500 mm long.
 104. The system of claim 92, whereinthe delivery apparatus further comprises a grip tube positioned aboutthe elongate shaft, wherein the grip tube is closer to the proximal endthan the distal end of the elongate shaft.
 105. A medical actuatorapparatus comprising: a fitting for coupling the apparatus to a proximalportion of a catheter, the fitting including a fitting lumen configuredto slidably receive an elongate member and to direct the elongate memberthrough a catheter lumen of the catheter; a plunger slidably engagedwith the fitting, the plunger including a plunger lumen configured toslidably receive the elongate member and to direct the elongate memberthrough the fitting lumen; wherein the plunger is configured toreversibly grip the elongate member such that moving the plungerdistally with respect to the fitting advances the elongate member withinthe catheter lumen when the apparatus is coupled to the catheter and theelongate shaft is gripped by the plunger; and an introducer configuredto be inserted through the fitting lumen and the plunger lumen, theintroducer including an introducer lumen configured to slidably receivethe elongate member, and wherein the elongate member may be loaded intothe fitting lumen and the plunger lumen of the apparatus by theintroducer, and further wherein the introducer is configured to beremoved from the apparatus following loading of the elongate member intothe fitting lumen and the plunger lumen of the apparatus.
 106. Thesystem of claim 105, wherein the plunger comprises a valve configured toreversibly grip the elongate shaft of the delivery apparatus.
 107. Thesystem of claim 105, wherein the actuator apparatus further comprises aspring member mounted between the plunger and the fitting to hold theplunger in a retracted position until a force is applied to slide theplunger distally with respect to the fitting.